/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.sanselan.palette;

import java.util.ArrayList;

import org.apache.sanselan.ImageWriteException;

public class QuantizedPalette extends Palette
{
	private final int precision;
	private final ArrayList subsets;
	private final ColorSpaceSubset straight[];

	public QuantizedPalette(ArrayList subsets, int precision)
	{
		this.subsets = subsets;
		this.precision = precision;

		{
			straight = new ColorSpaceSubset[1 << (precision * 3)];

			for (int i = 0; i < subsets.size(); i++)
			{
				ColorSpaceSubset subset = (ColorSpaceSubset) subsets.get(i);
				subset.setIndex(i);

				for (int u = subset.mins[0]; u <= subset.maxs[0]; u++)
					for (int j = subset.mins[1]; j <= subset.maxs[1]; j++)
						for (int k = subset.mins[2]; k <= subset.maxs[2]; k++)
						{
							int index = (u << (precision * 2))
									| (j << (precision * 1))
									| (k << (precision * 0));
							straight[index] = subset;
						}
			}
		}

	}

	public int getPaletteIndex(int rgb) throws ImageWriteException
	{
		int precisionMask = (1 << precision) - 1;

		int index = ((rgb >> (24 - 3 * precision)) & (precisionMask << (precision << 1)))
				| ((rgb >> (16 - 2 * precision)) & (precisionMask << precision))
				| ((rgb >> (8 - precision)) & (precisionMask));

		return straight[index].index;
	}

	public void dump()
	{
		//		System.out.println("ColorSpaceSubset.compares: "
		//				+ ColorSpaceSubset.compares);
		//		System.out.println("converted: " + converted);
		//		System.out.println("avg. distance: " + (distance / converted));
	}

	public int getEntry(int index)
	{
		ColorSpaceSubset subset = (ColorSpaceSubset) subsets.get(index);
		return subset.rgb;
	}

	public int length()
	{
		return subsets.size();

	}
}